I have been working at Nhibernate and Many to many relation is not working properly.
i am not getting idea how to save value in a junction table.

My code is Below
======================================My User Class==============================
public class Users
{
protected int _userid;
protected string _firstname;
protected string _lastname;
private ISet _Interest = new HashedSet();
public virtual void AddCategory(Interests interest)
{
//interest.User.Add(this);
interests.Add(interest);

}
}

=================================my User XML=============================
<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="DTO" namespace="Business.Entities">
<class name="Business.Entities.Users" table="Users" lazy="true">
<id name="UserId" column="UserId" type="int">
<generator class="native" />
</id>
<property type="string" length="50" name="FirstName" column="[FirstName]" />
<property type="string" length="50" name="LastName" column="[LastName]" />
<property type="Boolean" name="MaleInd" column="[MaleInd]" />
<property type="string" length="20" name="ContactNumber" column="[ContactNumber]" />
<property type="string" length="50" name="Email" column="[Email]" />
<property type="DateTime" name="ModificationDate" column="[ModificationDate]" />
<set name="interests" inverse="false" table="UserInterests" lazy="true" cascade="all">
<key column="UserId" />
<many-to-many class="Business.Entities.Interests">
<column name="InterestID" />
</many-to-many>
</set>
</class>
</hibernate-mapping>
=================================my interest class=============================

public class Interests
{
private int _interestid;
private string _interestdesc;
//private ISet user = new HashedSet();
private Users user;
}

}

=================================my interest XML=============================
<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="Business.Entities" assembly="DTO">
<class name="Business.Entities.Interests" table="Interests" lazy="true">
<id name="InterestId" column="InterestId" type="int">
<generator class="native" />
</id>
<property type="string" not-null="true" length="50" name="InterestDesc" column="[InterestDesc]" />
<set name="User" inverse="false" table="UserInterests" lazy="true" cascade="all">
<key column="InterestID" />
<many-to-many class="Business.Entities.Users">
<column name="UserId" />
</many-to-many>
</set>
</class>
</hibernate-mapping>

=================================my DAL====================================
Interests interest = new Interests();
interest.InterestDesc = "I like swimming";
Users user = (Users)session.Load(typeof(Users), 6);
interest.User=user;
user.interests.Add(interest);
session.Save(user);
session.Flush();



Now i Dont know how to add data in many to many relation database.
Can any body tell me how to solve it ... or some body could refer me to an example which should work too.

I am stuck here since 9 days... i mean 9 working days... :(

Two thinks for you to note:

- session.Save() on a perstsited object will give you a copy of the object or an exception with a primary key violation. Depends in the id generator

- If you have a bi-directional assocaition, one end has to be inverse